The present invention relates to a laser alignment devices for projecting a level laser beam, for sweeping a laser beam in a vertical plane, and for producing laser beams at right angles to each other.
In many applications, such as construction, there is a need to establish a level line in order to construct something which is level or varies by a measurable amount from a level line. In addition, for the construction of walls and other vertical structures, it is desirable to align the wall to be completely vertical. Where a corner of the building is being constructed, it is desirable to have the corner at an exact right angle so that once the square of the building is completed, the sides will match up.
One method of producing a level line with a laser beam is to mount a laser in an instrument so that the laser beam is directed downward to a pendulum-supported 90.degree. reflector which then sends out a horizontal laser beam. The reflector can also be rotatable, so that a scanning beam in a horizontal plane is generated. Such a system is shown in U.S. Pat. Nos. 4,221,483 and 4,679,937. One such rotating optical structure is referred to as a penta-prism. U.S. Pat. No. 4,062,634 shows a device which produces a scanning beam in a horizontal plane and can be turned on its side to produce a scanning beam in a vertical plane.
Some devices produce laser beams which are at 90.degree. with respect to each other for use in aligning corners of buildings, etc. One such system is shown in U.S. Pat. No. 4,836,669. Orthogonal fans of light are produced by using a cone-shaped reflector to deflect light in two directions. U.S. Pat. No. 3,897,637 shows a laser level and square which uses mirrors and beam splitters to produce orthogonal laser beams at the same time.